KOLDTECH SPKT-DOM-PM-914 Manual page 6

8. TROUBLE SHOOTING TABLE AND TROUBLE SHOOTING TREES
Symptoms Possible Cause
Compressor is 1. Main switch is disconnected
not run 2. Fuses are blown.
3. Thermal overload is tripped.
4. Magnetic contactor /coil is out of order
5. System shut down by safety devices.
6. Liquid line (or solenoid valve) is not
open.
7. Compressor Motor drive.
8. Loosened wiring.
9. (of 3 Phase system), Phase may be
lost.
Compressor is 1. Liquid refrigerant returns into
unusually crankcase.
sounded or 2. Refrigerant Pipe is not well erected
vibrated 3. Compressor mechanism loosened.
4. Internal balance springs or Neoprene
choke are broken
High 1. Condensation fail
discharge 2. System is overcharged refrigerant.
pressure 3. Fan is off
4. Condenser fins are dusty
Low 1. Compressor valve is damage
discharge 2. Insufficient refrigerant in system.
OASMs-2912-D/14/3/18
KOLDTECH
The Technology of Excellence
Actions
1. Close switch properly.
2. Check electrical circuit and motor
winding for shorted or grounded.
Investigate for possible overloading.
Replace fuse after fault is re-corrected.
3. Overload is automatically reset. Check
unit closely when unit resumes normal.
4. Repair or replace.
5. Determine type and cause of shutdown
and correct it before resetting safety
switch.
6. Check TXV, (Repair or replace coil.)
7. Check motor if opens windings, short
turn or burnt and disconnected.
8. Check all wires termination. Tighten all
the loosened screws.
9. Test all conductors continuity.
1. Check setting of expansion valves.
2. Provide proper fastener
3. Repair.
4. Replace.
1. Rectify cause of fails
2. Remove the excessive
3. Check electrical circuit.
4. Clean.
1. Check compression ratio or open it.
2. Check leaking and recharge refrigerant
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pressure 3. Stop valve is yet closed.
High suction 1. Excessive chilled product.
pressure 2. Expansion valve overfeeding.
Low suction 1. Lack of refrigerant.
pressure 2. Evaporator is full of ice
3. Clogged liquid line.
4. Expansion valve malfunctioning.
5. Improper TXV.
Compressor 1. Leaking of refrigerant.
loses oil 2. Loosened cylinder ring
3. Refrigerant flood back.
4. Pipe sizing or trapping is not correct
Compressor 1. Operating beyond design conditions.
thermal
2. Condenser fins are overly dirty
protector switch
3. Overcharged refrigerant
is open.
Evaporator Trouble shooting
Symptoms Possible Causes
Fan(s) is not turned. 1. Main switch is open.
2. Fuses are blown.
3. Motor is out of order.
4. Defective Timer or defrost
thermostat.
5. Unit is in defrosts cycle.
6. Coil is not cooled down
enough to reset thermostat.
Room temperature is too 1. Room temp. is overly set.
high. 2. Superheat is too high.
3. Refrigerant is shortage.
4. Evap. Coil is highly ice
accumulation.
OASMs-2912-D/14/3/18
KOLDTECH
The Technology of Excellence
3. Open stop valve properly.
1. Chilled volume to specification
2. Check remote bulb. Regulate superheat.
1. Check leaking and fix.
2. Defrost system does not work.
3. Replace Stainer-Drier
4. Check and reset for proper superheat.
5. Check for proper sizing.
1. Check leaking and recharge refrigerant.
2. Replace compressor.
3. Maintain proper superheat at
compressor.
4. Re-correct piping.
1. Tuning facilities to the allowable limits.
2. Clean Fin coil.
3. Release the excessive
Actions
1. Close switch.
2. Replace fuses. Check cause of short
circuits or overload conditions.
3. Replace motor.
4. Replace defective component.
5. Wait until resuming
6. Adjust fan delay setting or wait until
resuming.
1. Properly tune thermostat.
2. Adjust thermal expansion valve.
3. Check, fix leaking, and Recharge ref.
4. Do Manually defrost and check
defrost control setting
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